TCPServer: check if loop thread is running before waiting for it

src/tcp_server.cpp

@@ -27,6 +27,7 @@ TCPServer::TCPServer(int default_backlog, allocate_client_callback allocate_new_
 	: m_allocateNewClient(allocate_new_client)
 	, m_defaultBacklog(default_backlog)
 	, m_loopThread{}
+	, m_loopThreadRunning(false)
 #ifdef WITH_UPNP
 	, m_portMapping(0)
 #endif
@@ -473,7 +474,9 @@ void TCPServer::shutdown_tcp()
 	}
 #endif
 
-	uv_thread_join(&m_loopThread);
+	if (m_loopThreadRunning.load()) {
+		uv_thread_join(&m_loopThread);
+	}
 
 	uv_mutex_destroy(&m_bansLock);
 
@@ -573,6 +576,9 @@ bool TCPServer::send_internal(Client* client, Callback<size_t, uint8_t*, size_t>
 void TCPServer::loop(void* data)
 {
 	TCPServer* server = static_cast<TCPServer*>(data);
+	server->m_loopThreadRunning.exchange(true);
+	ON_SCOPE_LEAVE([server]() { server->m_loopThreadRunning.exchange(false); });
+
 	log_category_prefix = server->get_category();
 
 	LOGINFO(1, "event loop started");

src/tcp_server.h

@@ -149,6 +149,7 @@ protected:
 	int m_defaultBacklog;
 
 	uv_thread_t m_loopThread;
+	std::atomic<bool> m_loopThreadRunning;
 
 	static void loop(void* data);